RO water not exactly at 0 ppm

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eddieg115

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I recently installed a Hydrologic RO system to an outside spigot. I ran it for an hour to clear out and calibrate the system. After, I tested the RO versus Tap water with all three calibration lines, heres what i got:

1 Gallon:3 Gallon - RO = 5
1 Gallon:2 Gallon - RO = 7
1 Gallon:1 Gallon - RO = 11

Any idea as to why the RO water wont come to 0 ppm? Does it matter if the ppm is at 5 ppm?
 
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day_trippr

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I believe you need a DI stage to achieve literally "zero" TDS on a consumer-grade RO system. And then you'd have the corrosive DI water to deal with. It's not necessary to hit distilled water levels of impurities for brewing beer.

Imo, anything under 10 is respectable. My system takes my ~300 tds well water down to 9-10 for a 97% rejection rate on a 100gpd system (Filmtec TW30-1812-100HR membrane run at 75psi)...

Cheers!
 

VTX1300

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When I first installed my RO system it reduced my ~ 350 TDS tap water down to ~ 14. Now after almost a year and well over 200 gallons produced my TDS is usually in the 3 to 5 TDS range. Its my understanding that the RO membrane becomes more efficient as more water is run through the system. As day tripper said above 0 TDS is not necessary. anything under 10 is a good starting point for building brewing water.

If you are doing extract brews you are good to go. If doing all grain now you need to add back the proper salts needed by the style of beer you are brewing.
 

matt_m

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That sounds about like what I see out of the RO on mine. I get 0 out of the DI stage. Incoming city water sourced from Lake Erie is typically somewhere between > 150 and < 200.

I only use the DI water where I would use distilled water--CPAP machine humidifier, adding water to the battery on my backup sump pump battery, final rinse on my ph meter before putting it away, and zeroing my electronic refractometer. If I use 20 gallons a year I'd be surprised.
 

Bobby_M

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If you can detect flavor or any brewing related impact from 10ppm TDS, you're better than anyone. For all intents and purposes, call it zero when building the water back up.
 

SEndorf

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Any idea as to why the RO water wont come to 0 ppm? Does it matter if the ppm is at 5 ppm?
As others have pointed out, 0 ppm is not a goal. With any RO system anything below 20 is satisfactory.
You should not be looking for distilled numbers. Anything under 20 is considered good. My buckeye hydro system takes 380 ppm down to 5-7.
 

schematix

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Here is the water analysis test on the RO water that I buy and use for brewing. It is certainly not distilled water (which is probably a good thing). I think if I spent money on a purifying system, I would spend the money on a water analysis so I could accurately make adjustments.

https://centurysprings.com/wp-content/uploads/2020/03/2019-Water-Analysis-1.pdf
uh my tap water is more pure than that trash. would have been better to save your money you wasted on that water report and put it towards a cheapo RO system.
 

schematix

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I recently installed a Hydrologic RO system to an outside spigot. I ran it for an hour to clear out and calibrate the system. After, I tested the RO versus Tap water with all three calibration lines, heres what i got:

1 Gallon:3 Gallon - RO = 5
1 Gallon:2 Gallon - RO = 7
1 Gallon:1 Gallon - RO = 11

Any idea as to why the RO water wont come to 0 ppm? Does it matter if the ppm is at 5 ppm?
As others have mentioned, you are not only close enough for brewing purposes, but you're well within expected performance.

I actually prefer mine in the 15-20 ppm range for taste since i drink about a gallon of the stuff every day as plain drinking water. I've made it closer to 0 before and it just doesn't taste very good. It's almost rough and flat tasting.

Only benefit to 0 ppm i found is that it makes prettier ice cubes. They are usually crystal clear until the very center and very pleasant to chew on.
 
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I recently installed a Hydrologic RO system to an outside spigot. I ran it for an hour to clear out and calibrate the system. After, I tested the RO versus Tap water with all three calibration lines, heres what i got:

1 Gallon:3 Gallon - RO = 5
1 Gallon:2 Gallon - RO = 7
1 Gallon:1 Gallon - RO = 11

Any idea as to why the RO water wont come to 0 ppm? Does it matter if the ppm is at 5 ppm?
First, let's start with a little jargon: Rejection Rate.
Rejection Rate is the percentage of TDS the membrane does not allow to pass through to the purified water side of the membrane.

Most residential RO membranes has a factory spec rejection rate of 96 to 99%. So if your tap water reads 267 ppm tds, and your RO water reads 7 ppm tds, you have a 97% rejection rate.

So the TDS of the RO water is hugely affected by the TDS of your feed water. It doesn't really make sense to say something like "If your RO water isn't under 10 ppm something is wrong with your RO."

How much does tap water TDS vary across the country? We have customers with tap water below 50 ppm, and some over 2,800 ppm.

Russ
 
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Jim R

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uh my tap water is more pure than that trash. would have been better to save your money you wasted on that water report and put it towards a cheapo RO system.

I didn't spend anything on the water report. It is posted on the bottled water web site so I know exactly what I am starting with. Maybe this isn't what someone would call "true RO water". Who cares. There is no advantage to starting with distilled water. The most important thing is to know exactly what you are starting with based on a water report. Then you can easily and accurately make adjustments for each specific beer.

This bottled water only requires 1 gram of gypsum (Calcium sulfate) to brew my IPA's and have close to perfect water. Plus the water cost less than 90 cents per gallon and the water test was free.
 

schematix

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I didn't spend anything on the water report. It is posted on the bottled water web site so I know exactly what I am starting with. Maybe this isn't what someone would call "true RO water". Who cares. There is no advantage to starting with distilled water. The most important thing is to know exactly what you are starting with based on a water report. Then you can easily and accurately make adjustments for each specific beer.

This bottled water only requires 1 gram of gypsum (Calcium sulfate) to brew my IPA's and have close to perfect water. Plus the water cost less than 90 cents per gallon and the water test was free.
words mean things. That water is not even in the ballpark of RO water specs. Can it be used for brewing? For sure, but it’s not even close to RO water. I’d like to use it for coffee. Good spec for that.
 

Jayjay1976

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Mmmmm....water

I couldn't imagine shelling out each time I brew. I bought a decent RO setup on Amazon, it has given us great water for close to two years. When we moved I replaced all of the elements (prematurely I know) with higher-end stuff and upgraded the RO membrane to a GE Filmtech. We are on Chicago city water which isn't too bad and the RO output tastes mighty fine. My beers are still mediocre at best, but it sure ain't the RO water's fault.
 

Rob2010SS

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Mmmmm....water

I couldn't imagine shelling out each time I brew. I bought a decent RO setup on Amazon, it has given us great water for close to two years. When we moved I replaced all of the elements (prematurely I know) with higher-end stuff and upgraded the RO membrane to a GE Filmtech. We are on Chicago city water which isn't too bad and the RO output tastes mighty fine. My beers are still mediocre at best, but it sure ain't the RO water's fault.
Chicago water?! Where abouts are you located? Im in the NW burbs (Spring Grove)
 

Jayjay1976

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Chicago water?! Where abouts are you located? Im in the NW burbs (Spring Grove)
Um, west burbs. Further out than the El reaches but within reach of the Metra system. Apparently this area was served by a municipal well (really hard too) up until a couple of years ago. Everyone around here bitches about their water bills having doubled with the change, but the price seems fine to me having come from the city. Also, their appliances and water heaters, faucets, plumbing etc. should last a lot longer but people are short-sighted.
 

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I plan to buy an RO system really soon just waiting to see what my employers next move is tomorrow with layoffs. My well water is at 405 so if I can get down to those numbers I will be very happy. I can't even go to the store and get RO from the dispensers anymore as they shut them down.
 
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I plan to buy an RO system really soon just waiting to see what my employers next move is tomorrow with layoffs. My well water is at 405 so if I can get down to those numbers I will be very happy. I can't even go to the store and get RO from the dispensers anymore as they shut them down.
A good RO should get your 405 down to about 8 ppm TDS.

Russ
 

CaddyWampus

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Dang. After reading through this thread, I consider myself very lucky. At work, we have two 50 gpm RO units with a mixed bed DI system on top of that.

I have made beer with water taken after the ROs and taken after the mixed beds. If I recall, the water coming out of the RO units is around 5-6 TDS at any given time and I prefer the beer made with that water vs the DI water. So, to just continue parroting what others have said, 5 TDS is very acceptable for brewing.
 

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Ok, im new to this but what s wrong with using a DI filter? Whats so corrosive about it? Why is it bad for use i brewing ?
 

Jayjay1976

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Ok, im new to this but what s wrong with using a DI filter? Whats so corrosive about it? Why is it bad for use i brewing ?
From google:
"Why is reverse osmosis water corrosive?
For anyone who does not know, reverse osmosis finished water has a relatively low pH (in the range of 5-6) and little to no alkalinity or hardness to act as a buffer. Thereby, this finished water is quite aggressive on metal distribution piping existing prior to the installation and operation of the RO system."

So to put it simply, the RO+DI water, being devoid of ions, is hungry for any it can steal from whatever it comes into contact with including metals.
 

Jag75

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From google:
"Why is reverse osmosis water corrosive?
For anyone who does not know, reverse osmosis finished water has a relatively low pH (in the range of 5-6) and little to no alkalinity or hardness to act as a buffer. Thereby, this finished water is quite aggressive on metal distribution piping existing prior to the installation and operation of the RO system."

So to put it simply, the RO+DI water, being devoid of ions, is hungry for any it can steal from whatever it comes into contact with including metals.
I didnt know that . Good thing I use tap water to clean and run through my Grainfather and Cf5
 

deuc224

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Thanks Jayjay, that makes sense. Now does that apply to the minerals you add back into ur mash and sparge water? I just built a small (clone)HBrewO system with bigger filters and a final deionization filter and this now has me thinking. I will add minerals back into the mash and sparge water per brewfather specs, but is it worth it? Or do i omit the filter all together now? **** has me all paranoid, dont wanna end up with some irreversible thing lol.
 

Jayjay1976

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Thanks Jayjay, that makes sense. Now does that apply to the minerals you add back into ur mash and sparge water? I just built a small (clone)HBrewO system with bigger filters and a final deionization filter and this now has me thinking. I will add minerals back into the mash and sparge water per brewfather specs, but is it worth it? Or do i omit the filter all together now? poopy has me all paranoid, dont wanna end up with some irreversible thing lol.
Adding minerals back in even in minute quantities will effectively neutralize the corrosive tendencies of RO+DI water, so no worries when you are brewing. IMHO, the DI cartridge is totally unnecessary so you can just disconnect that. I dunno how your system is set up but mine has an activated carbon polishing cartridge just after the RO membrane, then it flows to the counter top tap.
 
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That inline taste and odor filter after the RO membrane is needed ONLY if the RO water is stored in a pressurized tank.

Russ
 

day_trippr

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No, it's mostly to clean up the "staleness" that water in a tank over time can exhibit.

btw, notice how much of an RO or RODI system is plastic...

Cheers!
 

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In regards to the corrosive tendencies of RO water do they then recommend not to run it thru copper pipe? I was going to just T into the existing line to my fridge and one faucet upstairs and just shut off the feed downstream. The RO system I ordered does not have the DI on it BTW. I am setting up the RO system in the basement next to the well tank, water softener, and all source pipes so it would have been an easy clean install for me but if that is not recommended then I can re-run new lines.
 

Jayjay1976

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No, it's mostly to clean up the "staleness" that water in a tank over time can exhibit.

btw, notice how much of an RO or RODI system is plastic...

Cheers!
PE and PP are two of the safest and most inert plastic resins ever developed. To gain food safety certification, not only the base resin but the FINISHED PARTS including release agents and colorants must also pass stringent extraction tests. The test consists of submersing the parts in a powerful solvent for a period of time, then analyzing the solvent for extractives via liquid chromatography. The US guidelines allow certain harmless extractives such as mineral oil and animal-sourced fats (mold release agent) up to a certain threshold. The EU and Japanese guidelines are even stricter, forbidding any extractives whatsoever though I believe they do permit washing the parts clean of mold release before performing the solvent test.
 
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day_trippr

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Not sure what that was all about, my point was quite simple (and contextually obvious): you don't find metal in RO systems...

Cheers!
 

deuc224

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Hey Jayjay, my set up is from tap to sediment filter, to carbon filter, to RO, to post active carbon filter, to deionization filter. Let me see if i can upload a pic of the set up, its almost like the HbrewO but just my take on it i guess.
 
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Jayjay1976

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Not sure what that was all about, my point was quite simple (and contextually obvious): you don't find metal in RO systems...

Cheers!
Sorry, I totally took your comment the wrong way. Thanks for setting me straight tho. Cheers!
 
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